I did a little programming in dart. There are many things to like. And I believe, at the time of writing, that Dart really is great for both java and js devs. Every object that is used has to be an instance of a class, and the event-driven style for reactive programming is pretty much 1:1 to how js does it. So it truly could become the sweet spot for UI development that is appealing to both types of devs.
I just wished it would have native tuples.